I. Field of the Invention
This invention relates generally to a rotor assembly for a tree mulching machine attachable to a skid loader, tractor or other work vehicle and more particularly to a rotor assembly for such tree mulching machine having a plurality of swinging hammers for downing and pulverizing trees.
II. Discussion of the Prior Art
Cutting machines have been used to clear brush and trees. It is important that these cutting machines work in an efficient and effective manner to assist land-clearing workers in their jobs. To this end, U.S. Pat. No. 6,871,485 is an important step forward for tree cutting machines. The '485 patent teaches a tree cutting attachment for a skid loader or other types of self-propelled work vehicles. The attachment is used to cut down brush and trees of tip to eight to ten inches in diameter. The attachment is made up of a motor-driven rotor assembly which is journaled within the frame of the attachment. The rotor assembly of the '485 patent comprises a cage-like mounting system having pockets in which tempered steel blades, approximately six inches in width, are bolted in side-by-side relationship. Two rows of blades are mounted 180° apart proximate the periphery of the rotor comprised of a series of parallel, generally circular plates that are welded to longitudinally extending rods. The knife blade elements are bolted to the blade holder with the non-sharpened end of the blade element abutting a flat steel bar that forms the part of the cage.
While the invention disclosed in the '485 patent is good for clearing brush and trees of a certain diameter over a certain terrain, there is proven to be a need for a tree cutting machine that is useful over a rougher terrain. For example, a terrain that has partially buried stumps and boulders may present problems for the prior art assemblies which use knife blades or fixed carbide teeth to cut. As an alternative, some have proposed using swinging hammer assemblies to cut the brush. For example, FAE USA, Inc. and Seppi, Inc. have developed a rotor assembly for their work vehicles which may be equipped with swinging hammers. Of course, wear and tear on the hammer is inevitable and therefore must eventually be replaced. The problem presented with the FAE and Seppi assembly is that the entire shalt of hammers must be pulled out of the machine in order to replace a single hammer. A further problem with the FAE assembly is that the entire shaft may need to be cut in order to remove it from the frame if the shaft itself is damaged. This takes the excavator out of operation for an unnecessarily long period of time.
Another commercially available mulching head includes the GyroTrac U.S.A. Inc. TOMA-AX model. The TOMA-AX also uses a swing tooth design with an individual tooth-mounting system combined with a spiral mounting pattern. The swinging teeth are protrusions on the drum of the rotor assembly. These protrusions on the drum cause the drum to jump when engaging a stump, boulder or the like. This reduces both the effectiveness and efficiency of the brush clearing machine and introduces shock loads to the entire machine that tend to shorten the life of the machine.
Therefore, there is a need in the prior art for a rotor assembly for a tree cutting machine which effectively allows for easy and efficient tree and brush clearing with an improved rotary cutting design over past inventions. The rotor cutting design must allow for individual replacement of swinging hammers, but such hammers must not protrude so as to cause the apparatus to jump when it engages a heavy object such as a partially buried stump or boulder.